function y_landmark = f_known_landmark(x, landmark_ne)

% x(1): north (X) coordinate of the robot
% x(2): east (Y) coordinate of the robot
% x(3): heading of the robot

% landmark_ne(1) : north coordinate of the landmark being observed
% landmark_ne(2) : east coordinate of the landmark being observed

% fill in the robot's measurement of the landmark; i.e., the landmark
% expressed in the robot coordinate frame
% 
trans = [ cos(x(3)) sin(x(3)) ( (-x(1))*cos(x(3))-x(2)*sin(x(3)) );
        -sin(x(3))  cos(x(3)) ( x(1)*sin(x(3))-x(2)*cos(x(3)) );
        0           0           1   ]; %transition matrix for clockwise rotation

pt = trans * [landmark_ne(1); landmark_ne(2); 1] ; 



% translated = [ landmark_ne(1) - x(1); 
%                landmark_ne(2) - x(2)];   
% 
% rot = [cos(x(3))  sin(x(3)); 
%        -sin(x(3))  cos(x(3))]; 
%    
% pt = rot * translated; 



y_landmark(1,1) = pt(1) ; % your code
y_landmark(2,1) = pt(2) ; % your code




